It doesn't look like he tried to self-arrest. I've never been in this situation, so maybe I'm missing something, but any idea why?

He let go of both tools right away, you could see them flying about, and then lost them altogether pretty early in the slide. If he had held on to one, he might have been able to but that opportunity was basically gone once they left his hands.

Dear Lord! Anybody know the injuries sustained? That guy hit some chunk for sure. He has to be busted up. My pucker factory nearly created a black hole while watching that. I'm sure I produced a few diamonds.

Effective self-arrest requires a lot of practice. A lot more than this guy seems to have had. It has to become second nature. Also, it looks like the leashes were loose around his wrists.

We once saw a girl fall upside down and backwards on hard, steep snow (like in this video) in Chamonix. She didn't have ice axes. She slid for about 1500 ft and was stopped just short of a 1000 rock cliff by her partner. As soon as she fell, her partner, without hesitation, grabbed his ice and jumped in after her. He self-arrested both of them.